Asphalt modifier and asphalt composition comprising the same

Abstract

The present invention relates to an asphalt modifier including a main chain of a vinyl aromatic hydrocarbon-conjugated diene block copolymer, and more particularly, to an asphalt modifier capable of effectively improving low-temperature properties, high-temperature properties, storage stability, and the like of an asphalt composition due to excellent compatibility with the asphalt composition when a vinyl aromatic hydrocarbon-conjugated diene block copolymer containing a certain multifunctional group is used as the asphalt modifier, and an asphalt composition including the same.

The invention claimed is: 
     
       1. An asphalt modifier comprising a multifunctional group bound to a main chain of a vinyl aromatic hydrocarbon-conjugated diene block copolymer represented by the following Formula 1: 
       
         
           
           
               
               
           
         
         wherein A to C blocks are each independently a vinyl aromatic hydrocarbon block or a conjugated diene block, 
         m, n, and o are each an integer greater than or equal to 1, 
         p is an integer in a range of 0<p≤3, and 
         a multifunctional group X is derived from a coupling agent, wherein the coupling agent comprises at least one of (2-chloroethyl)methyl dichlorosilane, (3-chloropropyl)methyl dichlorosilane, (4-chlorobutyl)methyl dichlorosilane, (3-chloropropyl)propyl dichlorosilane, bis(3-chloropropyl) dichlorosilane, or dichloro(chloromethyl) methylsilane. 
       
     
     
       2. The asphalt modifier according to  claim 1 , wherein the vinyl aromatic hydrocarbon block comprises at least one selected from the group consisting of styrene, α-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, and 4-(para-methylphenyl) styrene. 
     
     
       3. The asphalt modifier according to  claim 1 , wherein the conjugated diene block comprises at least one selected from the group consisting of 1,3-butadiene, 2,3-dimethyl-1,3-butadiene, and 2-phenyl-1,3-butadiene. 
     
     
       4. The asphalt modifier according to  claim 1 , wherein X is included at an amount of 40 to 4,700 ppm, based on the total weight 1 of the block copolymer. 
     
     
       5. The asphalt modifier according to  claim 1 , wherein the block copolymer has a weight average molecular weight of 30,000 to 500,000 g/mol. 
     
     
       6. A method of preparing an asphalt modifier of  claim 1 , comprising:
 preparing a vinyl aromatic hydrocarbon block by polymerizing a vinyl aromatic hydrocarbon-based monomer in a hydrocarbon-based solvent using a polymerization initiator; 
 preparing a vinyl aromatic hydrocarbon-conjugated diene block copolymer by mixing a polymerization initiator and a conjugated diene monomer with the vinyl aromatic hydrocarbon block and polymerizing the resulting mixture; and 
 performing a coupling reaction by mixing a coupling agent with the vinyl aromatic hydrocarbon-conjugated diene block copolymer, 
 wherein the coupling agent comprises (2-chloroethyl)methyl dichlorosilane, (3-chloropropyl)methyl dichlorosilane, (4-chlorobutyl)methyl dichlorosilane, (3-chloropropyl)propyl dichlorosilane, bis(3-chloropropyl) dichlorosilane, or dichloro(chloromethyl) methylsilane. 
 
     
     
       7. An asphalt composition comprising asphalt, a cross-linking agent, and an asphalt modifier,
 wherein the asphalt modifier is the asphalt modifier of  claim 1 .